Multifunctional polymers, method for the production and use thereof

ABSTRACT

Multifunctional polymers containing polymerized units of  
     (a) α-Acyloxyacrylonitrile, α-haloacrylic acid, α-acyloxyacrylic ester and/or α-hydroxyacrylic acid,  
     (b) monoethylenically unsaturated carboxylic acids,  
     (c) vinyl esters of saturated aliphatic monocarboxylic acids and/or vinyl alcohol and optionally  
     (d) other monoethylenically unsaturated monomers copolymerizable with said monomers (a) to (c) and optionally  
     (e) crosslinkers containing at least two ethylenically unsaturated double bonds  
     and having a K value of at least 7 (determined after H. Fikentscher in acetone at 25° C. and a polymer concentration of 1% by weight), processes for preparing multifunctional polymers by copolymerizing monomer mixtures of  
     (a) α-acyloxyacrylonitrile, α-haloacrylic acid and/or α-acyloxyacrylic ester,  
     (b) monoethylenically unsaturated carboxylic acids,  
     (c) vinyl esters of saturated aliphatic monocarboxylic acids and optionally  
     (d) other monoethylenically unsaturated monomers copolymerizable with said monomers (a) to (c) and optionally  
     (e) crosslinkers containing at least two ethylenically unsaturated double bonds  
     in the presence of polymerization initiators that form free radicals and partially or completely hydrolyzing the polymerized monomer units (a) and (c) in the copolymers thus obtainable and use of the multifunctional polymers in laundry detergents and cleaners, to bind polyvalent metal ions, as a stabilizer in textile bleaching and the bleaching of pulp for papermaking.

[0001] This invention relates to multifunctional polymers containingpolymerized units of

[0002] (a) α-acyloxyacrylonitrile, α-haloacrylic acid, α-acyloxyacrylicester and/or α-hydroxyacrylic acid,

[0003] (b) monoethylenically unsaturated carboxylic acids,

[0004] (c) vinyl esters of saturated aliphatic monocarboxylic acidsand/or vinyl alcohol and optionally

[0005] (d) other monoethylenically unsaturated monomers copolymerizablewith said monomers (a) to (c) and optionally

[0006] (e) crosslinkers containing at least two ethylenicallyunsaturated double bonds.

[0007] U.S. Pat. No. 2,728,746 discloses polymers of α-hydroxyacrylicacid which are prepared by polymerizing α-acyloxyacrylates optionallytogether with other monomers such as ethylene, styrene, acrylic acid ormethacrylic acid and subsequent hydrolysis of the polymerizedα-acyloxyacrylate units with bases. DE-A-24 31 823 discloses a processfor preparing water-soluble salts of poly-α-hydroxyacrylic acid byconverting α,β-dichloropropionic acid by thermal hydrogen chlorideelimination into α-chloroacrylic acid, then polymerizing theα-chloroacrylic acid in aqueous solution and treating the polymer withan aqueous solution of an alkali metal hydroxide or ammonia. Thewater-soluble salts of the thus obtainable poly-α-hydroxyacrylic acidare used for example as sequestrants for metal ions and as builders indetergents and cleaners.

[0008] EP-A-381 261 discloses nonaqueous liquid detergents which includea nonionic surfactant and a dispersed particulate phase which includes acarbonate, a mixture of carbonate and bicarbonate builder and acarboxyl-containing polymer, for example a copolymer of maleic acid andacrylic acid. According to the description part, usefulcarboxyl-containing polymers include poly-α-hydroxyacrylic acid. Theliquid laundry detergent may also include bleach.

[0009] DE-A-31 39 091 discloses phosphate-free or low-phosphate laundrydetergents and cleaners which include a polycarboxylic acid in saltform, an alkali metal heptoate or alkali metal gluconate, an alkalimetal silicate and an alkali metal hydroxide. Polycarboxylic acidscontemplated are in particular the polymers of acrylic acid,α-hydroxyacrylic acid, maleic acid, itaconic acid, mesaconic acid,arconitic acid, methylenemalonic acid and citraconic acid. Similarly thecopolymers of the carboxylic acids mentioned with each other or withethylenically unsaturated compounds such as ethylene, propylene, vinylether, vinyl acetate, furan, acrolein, acrylamide, acrylonitrile,methacrylic acid or crotonic acid are suitable polycarboxylic acids.EP-A-508 934 likewise discloses laundry detergent mixtures which includepolymers of hydroxyacrylic acid as builders.

[0010] EP-A-814 193 discloses a bleach stabilizer for peroxides whichincludes homo- or copolymers of α-hydroxyacrylic acid or water-solublesalts thereof, homo- or copolymers of acrylic acid, methacrylic acid andmaleic acid and, as a further component, diethylenetriaminepentaaceticacid, diethylenetetraminehexaacetic acid or water-soluble salts thereof.The three components have a synergistic effect when used as a bleachstabilizer for peroxides.

[0011] It is an object of the present invention to provide novelsubstances which have an improved effect compared to existing polymersbased on α-hydroxycarboxylic acid.

[0012] We have found that this object is achieved by multifunctionalpolymers containing polymerized units of

[0013] (a) α-acyloxyacrylonitrile, α-haloacrylic acid, α-acyloxyacrylicester and/or α-hydroxyacrylic acid,

[0014] (b) monoethylenically unsaturated carboxylic acids,

[0015] (c) vinyl esters of saturated aliphatic monocarboxylic acidsand/or vinyl alcohol and optionally

[0016] (d) other monoethylenically unsaturated monomers copolymerizablewith said monomers (a) to (c) and optionally

[0017] (e) crosslinkers containing at least two ethylenicallyunsaturated double bonds and having a K value of at least 7 (determinedafter H. Fikentscher in acetone at 25° C. and a polymer concentration of1% by weight).

[0018] The invention also contemplates a process for preparingmultifunctional polymers, which comprises copolymerizing monomermixtures of

[0019] (a) α-acyloxyacrylonitrile, α-haloacrylic acid and/orα-acyloxyacrylic ester,

[0020] (b) monoethylenically unsaturated carboxylic acids,

[0021] (c) vinyl esters of saturated aliphatic monocarboxylic acids andoptionally

[0022] (d) other monoethylenically unsaturated monomers copolymerizablewith said monomers (a) to (c) and optionally

[0023] (e) crosslinkers containing at least two ethylenicallyunsaturated double bonds

[0024] in the presence of polymerization initiators that form freeradicals and partially or completely hydrolyzing the polymerized monomerunits (a) and (c) in the copolymers thus obtainable.

[0025] Preferably monomer mixtures of

[0026] (a) from 2 to 98 mol % of α-acyloxyacrylonitrile, α-haloacrylicacid and/or α-acyloxyacrylic ester,

[0027] (b) from 1 to 95 mol % of monoethylenically unsaturatedcarboxylic acids,

[0028] (c) from 1 to 90 mol % of vinyl esters of saturated aliphaticmonocarboxylic acids and optionally

[0029] (d) from 0 to 20 mol % of other monoethylenically unsaturatedmonomers copolymerizable with said monomers (a) to (c) and

[0030] (e) from 0 to 10 mol % of crosslinkers containing at least twoethylenically unsaturated double bonds,

[0031] the percentages (a) to (e) always adding up to 100, arecopolymerized and the units (a) and (c) in the copolymers thusobtainable are partially or completely hydrolyzed.

[0032] α-Acyloxyacrylonitrile and α-acyloxyacrylic esters can becharacterized for example by means of the following formula:

[0033] where X=—CN or

[0034] R=H, C₁-C₆-alkyl, aryl and

[0035] R¹=OH, C₁-C₆-alkoxy, C₁-C₆-alkyl, aryl and

[0036] C₅-C₈-cycloalkyl.

[0037] Examples of α-acyloxyacrylonitriles are α-acetoxyacrylonitrile,α-propionyloxyacrylonitrile and α-butyryloxyacrylonitrile.

[0038] α-Acyloxyacrylic esters of the formula I where X=CO—R¹ andR=C₁-C₆-alkyl are for example methyl α-acetoxyacrylate (R=CH₃, R¹=OCH₃),ethyl α-acetoxyacrylate (R=CH₃, R¹=OC₂H₅),n-propyl α-acetoxyacrylate(R=CH₃, R¹=OCH₂CH₂CH₃), isopropyl α-acetoxyacrylate (R=CH₃,R¹=OCH(CH₃)₂), n-butyl α-acetoxyacrylate ((R=CH₃, R¹=O(CH₂)₃CH₃),isobutyl α-acetoxyacrylate, isodecyl α-acetoxyacrylate, methylα-propionyloxyacrylate (R=C₂H₅, R¹=OCH₃), ethyl α-propionyloxyacrylate(R=C₂H₅, R¹=OC₂H₅), methyl α-butyryloxyacrylate (R=C₃H₇, R¹=OCH₃) andethyl α-butoxyacrylate.

[0039] The term α-acyloxyacrylic ester shall also comprehend suchcompounds as, after polymerization and hydrolysis, give rise to polymerscontaining α-hydroxyacrylic acid units. These include for example cyclicacyloxyacrylates of the formulae

[0040] where R³ and R⁴ are identical or different and each is H, CH₃,Et, Pr, i-Pr, n-Bu, i-Bu, aryl or substituted aryl.

[0041] The compound of the formula II is a cyclic acyloxyacrylate(3,6-bis(methylene)-1,4-dioxan-2,5-dione) and the compounds of theformula III are cyclic acetals of the 5-methylene-1,3-dioxolan-4-onetype whose acetal component is derived for example from an aldehyde suchas formaldehyde, acetaldehyde, propionaldehyde, isobutyraldehyde orbenzaldehyde or from a ketone such as acetone, methyl ethyl ketone orcyclohexanone (R³, R⁴=alkyl, aralkyl).

[0042] Examples of useful α-haloacrylic acids are α-chloroacrylic acidand α-bromoacrylic acid.

[0043] The multifunctional polymers contain as component (b) polymerizedunits of monoethylenically unsaturated carboxylic acids, for exampleacrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconicacid, fumaric acid, mesaconic acid, aconitic acid, methylenemalonic acidand citraconic acid. Among this group of monomers preference is given tousing acrylic acid, methacrylic acid, maleic acid and maleic anhydride.

[0044] As component (c) the multifunctional polymers contain vinylesters of saturated aliphatic monocarboxylic acids in polymerized form.The vinyl esters are derived for example from monobasic saturatedcarboxylic acids having 2-18 carbon atoms. Examples thereof are vinylacetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinylpalmitate, vinyl stearate and vinyl laurate. The copolymerization can becarried out using for example a single vinyl ester or else a mixture oftwo different vinyl esters, for example mixtures of vinyl acetate andvinyl propionate or mixtures of vinyl acetate and vinyl butyrate. Amongthis group of monomers preference is given to using vinyl acetate.

[0045] Other monoethylenically unsaturated monomers copolymerizable withthe monomers (a) to (c) are for example acrylonitrile,methacrylonitrile, acrylamide, methacrylamide, acrolein, ethylene,isobutylene, propylene, diisobutene, styrene,acrylamido-2-methyl-propanesulfonic acid, vinylsulfonic acid,allylsulfonic acid, methallylsulfonic acid, vinylphosphonic acid,allylphosphonic acid, dimethylaminoethyl acrylate, diethylaminoethylacrylate, diethylaminoethyl methacrylate, N-vinylpyrrolidone,N-vinylformamide, N-vinylimidazole, N-vinylimidazoline,1-vinyl-2-methylimidazole, 1-vinyl-2-methylimidazoline and hydroxyalkylesters having 2-6 carbon atoms in the hydroxyalkyl group ofmonoethylenically unsaturated carboxylic acids containing 3-6 carbonatoms such as hydroxyethyl acrylate, hydroxyethyl methacrylate,hydroxy-n-propyl acrylate, hydroxyisopropyl acrylate and hydroxyisobutylacrylate. The monomers which contain free acid groups, for example vinylsulfonate, can also be used in the form of the alkali metal and ammoniumsalts in the copolymerization.

[0046] Monomers of group (e) which contain at least two ethylenicallyunsaturated double bonds are customarily referred to as crosslinkers.Suitable crosslinkers are for example diacrylates or dimethacrylates ofat least dihydric saturated alcohols, for example ethylene glycoldiacrylate, ethylene glycol dimethacrylate, 1,2-propylene glycoldiacrylate, 1,2-propylene glycol dimethacrylate, 1,4-butanedioldiacrylate, 1,4-butanediol dimethacrylate, hexanediol diacrylate,hexanediol dimethacrylate, neopentylglycol diacrylate, neopentylglycoldimethacrylate, 3-methylpentanediol diacrylate and 3-methylpentanedioldimethacrylate. Similarly, the acrylic and methacrylic esters ofalcohols having more than 2 OH groups can be used as crosslinkers, forexample trimethylolpropane triacrylate or trimethylolpropanetrimethacrylate. A further class of crosslinkers are diacrylates ordimethacrylates of polyethylene glycols or polypropylene glycols eachhaving molecular weights of from 200 to 9000. Polyethylene glycols andpolypropylene glycols used for the preparation of the diacrylates ordimethacrylates preferably have a molecular weight of from 400 to 2000in each case. As well as the homopolymers of ethylene oxide or propyleneoxide it is also possible to use block copolymers of ethylene oxide andpropylene oxide or random copolymers of ethylene oxide and propyleneoxide. Similarly, the oligomers of ethylene oxide and propylene oxideare suitable for preparing crosslinkers, for example diethylene glycoldiacrylate, diethylene glycol dimethacrylate, triethylene glycoldiacrylate, triethylene glycol dimethacrylate, tetraethylene glycoldiacrylate and/or tetraethylene glycol dimethacrylate.

[0047] Useful crosslinkers further include vinyl esters of ethylenicallyunsaturated C₃-C₆-carboxylic acids, for example vinyl acrylate, vinylmethacrylate or vinyl itaconate. Useful crosslinkers further includevinyl esters of saturated carboxylic acids containing at least 2carboxyl groups and also di- and polyvinyl ethers of at least dihydricalcohols, for example divinyl adipate, butanediol divinyl ether,trimethylolpropane trivinyl ether. Further crosslinkers are allyl estersof ethylenically unsaturated carboxylic acids, for example allylacrylate and allyl methacrylate, allyl ethers of polyhydric alcohols,for example pentaerithritol triallyl ether, triallylsucrose andpentaallylsucrose. Useful crosslinkers further includemethylenebismethacrylamide, divinylethyleneurea, divinylpropyleneurea,divinylbenzene, divinyldioxane, tetraallylsilane and tetravinylsilane.

[0048] The multifunctional polymers preferably contain copolymerizedunits (a) of α-hydroxyacrylic acid and units (c) of partially orcompletely hydrolyzed vinyl esters of saturated monocarboxylic acids andhave a K value of at least 6 (determined after H. Fikentscher in waterat 25° C. and a polymer concentration of 1% by weight). Themultifunctional polymers contain for example polymerized units of

[0049] (a) from 2 to 98 mol % of α-acyloxyacrylonitrile, α-haloacrylicacid, α-acyloxyacrylic ester and/or α-hydroxyacrylic acid,

[0050] (b) from 1 to 95 mol % of at least one monoethylenicallyunsaturated carboxylic acid,

[0051] (c) from 1 to 90 mol % of at least one vinyl ester of saturatedaliphatic monocarboxylic acids and/or vinyl alcohol,

[0052] (d)from 0 to 20 mol % of other monoethylenically unsaturatedmonomers copolymerizable with said monomers (a) to (c) and

[0053] (e) from 0 to 10 mol % of a crosslinker containing at least twoethylenically unsaturated double bonds,

[0054] the mol % ages always adding up to 100.

[0055] Preferred multifunctional polymers contain polymerized units of

[0056] (a) from 5 to 95 mol % of α-acyloxyacrylonitrile, α-haloacrylicacid, α-acyloxyacrylic ester and/or α-hydroxyacrylic acid,

[0057] (b) from 2 to 90 mol % of at least one monoethylenicallyunsaturated carboxylic acid,

[0058] (c) from 2 to 70 mol % of at least one vinyl ester of saturatedaliphatic monocarboxylic acids and/or vinyl alcohol, and

[0059] (d) from 0 to 15 mol % of other monoethylenically unsaturatedmonomers copolymerizable with said monomers (a) to (c),

[0060] the mol % ages always adding up to 100.

[0061] Particular preference is given to those polymers as containpolymerized units of

[0062] (a) from 10 to 90 mol % of α-acyloxyacrylonitrile, α-haloacrylicacid, α-acyloxyacrylic ester and/or α-hydroxyacrylic acid,

[0063] (b) from 5 to 80 mol % of at least one monoethylenicallyunsaturated carboxylic acid,

[0064] (c) from 5 to 60 mol % of at least one vinyl ester of saturatedaliphatic monocarboxylic acids and/or vinyl alcohol, and

[0065] (d) from 0 to 10 mol % of other monoethylenically unsaturatedmonomers copolymerizable with said monomers (a) to (c),

[0066] the mol % ages always adding up to 100. These polymers usuallycontain copolymerized units of

[0067] (a) from 5 to 95 mol % of α-hydroxyacrylic acid,

[0068] (b) from 2 to 90 mol % of acrylic acid, methacrylic acid, maleicacid and/or maleic anhydride, and

[0069] c) from 2 to 70 mol % of vinyl acetate and/or vinyl alcohol,

[0070] the mol % ages always adding up to 100.

[0071] The multifunctional polymers are prepared by polymerizing themonomers (a) to (e) in the presence of polymerization initiators thatform free radicals and subsequent partial or complete hydrolysis of thepolymerized monomer units (a) and (c). Hydrolysis of the polymerizedmonomer units (a) creates α-hydroxyacrylic acid units. The polymerizedα-acyloxyacrylonitrile units likewise give rise to α-hydroxyacrylic acidunits in the form of their salts, for example under the action ofaqueous bases to eliminate the α-acyl group and completely hydrolyze thenitrile group. The alkaline hydrolysis of polymers containingpolymerized units of α-haloacrylic acid produces, through elimination ofthe halogen group, polymers containing α-hydroxyacrylic acid units.Polymers containing polymerized units of α-acyloxyacrylic esters arelikewise hydrolyzed to polymers containing α-hydroxyacrylic acid units,by hydrolysis of the ester groups. Hydrolysis can be partial orcomplete. The copolymers are usually hydrolyzed to such an extent thatwater-soluble or at least water-dispersible copolymers are formed. Thedegree of hydrolysis is for example in the range from 10 to 100% ,preferably from 50 to 100% .

[0072] The polymerization of the monomers (a) to (e) is carried outaccording to known processes in the manner of a solution, precipitationor emulsion polymerization. It can also be carried out as a bulkpolymerization. The polymerization temperatures are for example in thetemperature range of 50-150° C., preferably 60-130° C. Thecopolymerization can be carried out at atmospheric pressure, underreduced pressure or else under elevated pressure, for example atpressures of up to 20 bar. Useful solvents for a solution polymerizationinclude for example hydrocarbons such as toluene and xylene,C₁-C₆-alcohols such as methanol, ethanol, isopropanol, n-propanol,isobutanol, n-butanol, tert-butanol, n-hexanol and cyclohexanol orketones such as methyl ethyl ketone or acetone.

[0073] The emulsion polymerization is preferably carried out in water inthe absence or presence (in amounts of up to 20% by weight, based on thereaction mixture) of surface-active substances. Preferred reaction mediafor the polymerization of the monomers are alcohols, aromatichydrocarbons and water. The polymerization is initiated using customaryinitiators such as peroxides, for example perbenzoate, perpivalate andperoctoate, hydrogen peroxide, persulfates and azo compounds such asazobisisobutyronitrile or water-soluble azo compounds such as2,2′-azobis(2-amidinopropane) dihydrochloride. The polymerization may becarried out in the presence of regulators, if desired. Useful regulatorsinclude all known regulating substances. Preferred regulators containsulfur in bonded form such as dodecyl mercaptan, 2-mercaptoacetic acid,mercaptopropionic acid, 2-mercaptoethanol and mercaptobutanol. When asolvent or diluent is used in the polymerization, the solids content ofthe reaction mixture is for example in the range from 10 to 70% ,preferably from 20 to 60% , by weight.

[0074] The copolymers are hydrolyzed following the polymerization. Thehydrolysis can be carried out not only in the basic but also in theacidic pH range, except for polymers containing polymerized units ofα-haloacrylic acid. However, polymers containing α-haloacrylic acidunits can only be polymerized with bases. In most cases, one equivalentof a hydrolyzable group requires one equivalent of a base or acid.However, the bases or acids can be used up to an excess of 1.5,preferably up to 1.2, equivalents per hydrolyzable group. A base can beadded all at once or continuously. It is also possible to initiallycharge a base and to add the polymer which is to be hydrolyzed to it allat once or continuously or batchwise. Useful bases for the hydrolysisare in particular alkali metal hydroxides such as sodium hydroxide orpotassium hydroxide, ammonia or amines.

[0075] When the hydrolysis is carried out using an acid, catalyticamounts will be sufficient, for example from 0.01 to 0.1 equivalent ofan acid per equivalent of the group to be hydrolyzed. The hydrolysis canbe carried out at for example from 20 to 220° C., preferably at from 50to 150° C. The hydrolysis is carried out in pressure tightly sealedapparatus at temperatures above the boiling point of water. If thepolymerization has been carried out in an organic solvent, some or allof the organic solvent can be distilled off during the hydrolysis.Similarly, the alcohols released from α-acyloxyacrylic ester unitsduring the hydrolysis can be distilled out of the reaction mixture, forexample.

[0076] The hydrolysis of the polymerized units of vinyl esters ofsaturated monocarboxylic acids to form vinyl alcohol units is preferablycarried out using alkali metal hydroxides. The copolymers preferablycontain polymerized units of vinyl acetate as monomer c). The hydrolysisof the polymerized units c) is effected either partially, for example toan extent from 10 to 99% , or completely. The hydrolyzed copolymersusually still contain from 50 to 0.1% of unhydrolyzed vinyl ester units.

[0077] Usually monomer mixtures of

[0078] a) from 2 to 98 mol % of α-acyloxyacrylonitrile, α-haloacrylicacid and/or α-acyloxyacrylic ester,

[0079] b) from 1 to 95 mol % of monoethylenically unsaturated carboxylicacids,

[0080] c) from 1 to 90 mol % of at least one vinyl ester of an aliphaticmonocarboxylic acid,

[0081] d) from 0 to 20 mol % of other monoethylenically unsaturatedmonomers copolymerizable with said monomers (a) to (c) and

[0082] e) from 0 to 10 mol % of a crosslinker containing at least twoethylenically unsaturated double bonds,

[0083] the percentages (a) to (e) always adding up to 100, arecopolymerized and the units (a) and (c) in the copolymers thusobtainable are partially or completely hydrolyzed.

[0084] Particular preference is given to a process variant wherein

[0085] (a) from 5 to 95 mol % α-acyloxyacrylonitrile, α-chloroacrylicacid and/or α-acetoxyacrylic ester,

[0086] (b) from 2 to 90 mol % of acrylic acid, methacrylic acid, maleicacid and/or maleic anhydride and

[0087] (c) from 2 to 70 mol % of vinyl acetate

[0088] are copolymerized, the mol % ages always adding up to 100, andthe polymerized units (a) and (c) in the copolymers are partially orcompletely hydrolyzed.

[0089] The above-described multifunctional polymers are used in laundrydetergents and cleaners, to bind polyvalent metal ions, as a stabilizerin textile bleaching and the bleaching of fiber pulps for papermaking.When used in laundry detergents, the polymers provide not only anincrustation inhibition but also an augmentation of the primarydetergency and at the same time stabilize the bleaches such asperborates or percarbonates.

[0090] The copolymers are used for example in amounts from 1 to 20% ,preferably from 2 to 10%, by weight in laundry detergents and cleaners,in each case based on the entire formulation. The amounts ofmultifunctional polymer used in textile bleaching and the bleaching ofpaper stock range for example from 1 to 20% by weight, based on theaqueous bleach mix.

[0091] The copolymers of the invention are also excellent complexingagents for polyvalent metal ions such as calcium, iron, manganese andcopper ions.

[0092] The K values of the polymers were determined after H. FikentscherCellulose-Chemie, volume 13, 58-64 and 71-74 (1932). The K valuedetermination for the unhydrolyzed copolymers was carried out in acetoneat 25° C. and a polymer concentration of 1% by weight. The K value ofthe hydrolyzed copolymers—provided the copolymers were completelysoluble in water—was carried out in water at 25° C. and a polymerconcentration of 1% by weight.

[0093] Unless otherwise stated (as in the case of comparative example2), the hydrolysis was carried out in each case using 100% of the amountof base theoretically required to completely hydrolyze and neutralizeall COOH groups.

INVENTIVE EXAMPLE 1

[0094] Terpolymer prepared from 82 mol % of ethyl α-acetoxyacrylate, 10mol % of acrylic acid and 8 mol % of vinyl acetate.

[0095] In a 250 ml multi-neck glass flask equipped with a paddlestirrer, a reflux condenser, an internal thermometer and two droppingfunnels, an initial charge of 25 g of isopropanol was heated to 85° C.in an oil bath under a nitrogen atmosphere. On reaching 85° C. meteringwas started of a 3 hour addition of a mixture of 72 g (0.4557 mol) ofethyl α-acetoxyacrylate, 4 g (0.0556 mol) of acrylic acid and 4 g(0.00465 mol) of vinyl acetate and concurrently a 6 hour addition of amixture of 3.2 g of tert-butyl peroxide and 20 g of isopropanol. Thecopolymerization was carried out at 85° C. On completion of theinitiator addition the reaction mixture was postpolymerized at 85° C.for 1.5 hours and then diluted with 80 g of isopropanol. The solutionsolidified on cooling. The solids content of the solution was 37.6%. Thecopolymer had a K value of 19.1 (determined in acetone at 25° C. and apolymer concentration of 1% by weight).

[0096] Hydrolysis:

[0097] In a 1 liter capacity stirred pot equipped with a refluxcondenser, a distillation apparatus, an internal thermometer and ananchor stirrer, an initial charge of 172 g of the above-describedpolymer solution was heated in an oil bath at an oil bath temperature of110° C. 134 g of a 25% by weight aqueous sodium hydroxide solution(0.8375 mol of NaOH) were added and at the same time isopropanol wasdistilled off until the internal temperature (temperature of thereaction mixture) had risen to 100° C. The thickening mass was dilutedwith 100 g of water and maintained at 100° C. for a further two hours.During this time a total of 400 g of water were added. The remainingisopropanol was removed from the reaction mixture under a reducedpressure of about 700 mbar to leave a clear orange solution having asolids content of 13.9%. The copolymer had a K value of 20.5 (determinedin 1% aqueous solution at 25° C.).

INVENTIVE EXAMPLE 2

[0098] Terpolymer prepared from 67 mol % of ethyl α-acetoxyacrylate, 18mol % of acrylic acid and 15 mol % of vinyl acetate.

[0099] The apparatus described in inventive example 1 was initiallycharged with 25 g of isopropanol. The monomer feed was composed of 64 g(0.4051 mol) of ethyl α-acetoxyacrylate, 8 g (0.1111 mol) of acrylicacid and 8 g (0.0930 mol) of vinyl acetate. The initiator feed was as ininventive example 1 a solution of 3.2 g of tert-butyl peroxide in 20 gof isopropanol. The monomer feed stream was metered into the initialcharge in the course of three hours and the initiator in the course of 6hours. The coolymerization took place at 85° C. The postpolymerizationtime was two hours. The reaction mixture was then diluted with 138 g ofisopropanol to obtain a liquid which was very cloudy at room temperatureand had a solids content of 28.6%. The K value of the copolymer was 19.8(measured in 1% solution in acetone at 25° C.).

Hydrolysis

[0100] 238 g of the above-described reaction mixture was hydrolyzed asdescribed in inventive example 1 by adding 145 g of a 25% by weightaqueous sodium hydroxide solution (0.9063 mol of NaOH) and distillingoff isopropanol at the same time. Hydrolysis for about 30 minutesyielded a viscous yellow mass which was diluted with 100 g of water toform a coarse suspension. After the temperature of the reaction mixturehad risen to 100° C., the reaction mixture was stirred at thattemperature for two hours and admixed with 200 g of water. Theisopropanol remaining in the reaction mixture was distilled out of themixture at a pressure of about 700 mbar. The result was a light red,cloudy solution having a solids content of 23.2%. The copolymer had a Kvalue of 22.4 (determined in aqueous solution and at a concentration of1% by weight and 25° C.).

INVENTIVE EXAMPLE 3

[0101] Terpolymer prepared from 54 mol % of ethyl α-acetoxyacrylate, 17mol % of acrylic acid and 29 mol % of vinyl acetate.

[0102] The copolymerization was carried out similarly to the directionsin inventive example 1, except that the monomer feed was composed of 56g (0.3544 mol) of ethyl α-acetoxyacrylate, 8 g (0.1111 mol) of acrylicacid and 16 g (0.1860 mol) of vinyl acetate. The postpolymerization timewas 2 hours. 80 g of isopropanol were added as diluent to form a clearcolorless polymer solution having a solids content of 36.2%. Thecopolymer had a K value of 19.1 (measured in acetone at 25° C. and apolymer concentration of 1% by weight).

Hydrolysis

[0103] 178 g of the above-described polymer solution were initiallycharged to a 1 liter stirred pot equipped with reflux condenser,distillation apparatus, internal thermometer and anchor stirrer andheated in an oil bath having a temperature of 100° C. As soon as theinternal temperature was 50° C., 137.6 g of 25% by weight aqueous sodiumhydroxide solution (0.86 mol of NaOH) were added over 15 minutes andisopropanol was distilled off to leave a yellow suspension which wasdiluted with 300 g of water. The remaining isopropanol was removed fromthe mixture at 700 mbar and 85° C. to leave a clear yellowish orangepolymer solution having a solids content of 22.1%. The copolymer had a Kvalue of 22.4 (determined in 1% aqueous solution at 25° C.).

INVENTIVE EXAMPLE 4

[0104] Terpolymer prepared from 54 mol % of ethyl α-acetoxyacrylate, 17mol % of acrylic acid and 29 mol % of vinyl acetate.

[0105] The polymerization described in inventive example 3 was repeatedwith the exceptions that the initiator used was a mixture of 7.2 g oftert-butyl perpivalate in the form of a 75% by weight solution inaliphatics and 17 g of isopropanol and the monomer stream was metered inover five hours and the initiator over six hours. A two hourpostpolymerization time and dilution of the batch with 80 g ofisopropanol afforded a clear colorless polymer solution having a solidscontent of 35.5%. The polymer had a K value of 13.4 (measured in 1%solution in acetone at 25° C.).

Hydrolysis

[0106] 116 g of the above-described polymer solution were heated to aninternal temperature of 110° C. by means of an oil bath. As soon as thetemperature had reached 50° C., 125.2 g of a 25% by weight aqueoussolution of potassium hydroxide (0.5579 mol of KOH) were graduallyadded. The reaction mixture was then maintained at 110° C. for twohours. Isopropanol was then distilled off at 700 mbar and 85° C. toleave a clear yellowish orange polymer solution having a solids contentof 27.3%. The K value of the polymer was 13.3 (determined in aqueoussolution at 25° C. and a polymer concentration of 1%).

INVENTIVE EXAMPLE 5

[0107] Terpolymer prepared from 53 mol % of ethyl α-acetoxyacrylate, 33mol % of acrylic acid and 14 mol % of vinyl acetate.

[0108] The polymerization was carried out similarly to inventive example1 except that the monomer feed used was 56 g (0.3544 mol) of ethylα-acetoxyacrylate, 16 g (0.2222 mol) of acrylic acid and 8 g (0.0930mol) of vinyl acetate and the initiator feed was 3.2 g of tert-butylperoxide in 55 g of isopropanol. The postpolymerization time was twohours. In departure from the method of example 1, 45 g of isopropanolwere added to obtain a clear yellow polymer solution having a solidscontent of 37.9%. The K value of the copolymer was 19.0 (determined in1% solution in acetone at 25° C.).

Hydrolysis

[0109] 180 g of the above-described polymer solution were heated up inthe apparatus described in inventive example 1, in an oil bath heated to110° C., and hydrolyzed according to the method indicated in inventiveexample 1 by addition of 142 g of 25% by weight aqueous sodium hydroxidesolution (0.8875 mol of NaOH). Isopropanol was distilled off at the sametime. After about 15 minutes this afforded a yellow suspension which wasdiluted to a clear solution with 200 g of water. The remainingisopropanol was removed from the mixture at 85° C. under a pressure ofabout 700 mbar to leave a clear dark yellow polymer solution having asolids content of 27.5%. The copolymer had a K value of 27.4 (determinedin 1% aqueous solution at 25° C.).

INVENTIVE EXAMPLE 6

[0110] Terpolymer prepared from 44 mol % of ethyl α-acetoxyacrylate, 16mol % of acrylic acid and 40 mol % of vinyl acetate.

[0111] The polymerization described in inventive example 1 was repeatedexcept that the monomer feed used was 48 g (0.3038 mol) of ethylα-acetoxyacrylate, 8 g (0.1111 mol) of acrylic acid and 24 g (0.2791mol) of vinyl acetate and the reaction mixture was postpolymerized fortwo hours to afford a clear yellow polymer solution having a solidscontent of 35.0%. The copolymer had a K value of 29.7 (determined in 1%solution in acetone at 25° C.).

Hydrolysis

[0112] 157 g of the above-described copolymer solution in isopropanolwere heated in a 1 liter capacity stirred pot equipped with refluxcondenser, distillation apparatus, internal thermometer and anchorstirrer to an internal temperature of 80° C. As soon as the temperaturehad reached 50° C., 120 g of 25% by weight aqueous sodium hydroxidesolution (0.75 mol of NaOH) and 200 g of water were slowly addedconcurrently and the batch was then diluted with 300 g of water.Isopropanol was distilled off during the hydrolysis. The remainingisopropanol was removed from the reaction mixture at 85° C. under apressure of about 700 mbar to leave a clear dark red solution having asolids content of 13.0%. The copolymer had a K value of 26.7 (determinedin 1% aqueous solution at 25° C.).

INVENTIVE EXAMPLE 7

[0113] Terpolymer prepared from 34 mol % of ethyl α-acetoxyacrylate, 15mol % of acrylic acid and 51 mol % of vinyl acetate.

[0114] Inventive example 1 was repeated with the exceptions that amonomer mixture of 40 g (0.2532 mol) of ethyl α-acetoxyacrylate, 8 g(0.1111 mol) of acrylic acid and 32 g (0.373 mol) of vinyl acetate wereused and the reaction mixture was postpolymerized for two hours toafford a clear yellow polymer solution having a solids content of 34.3%.The K value of the copolymer was 28.0 (determined in 1% solution inacetone at 25° C.).

Hydrolysis

[0115] 166 g of the above-described polymer solution in isopropanol wereinitially charged to the hydrolysis apparatus described in inventiveexample 1 and heated to an internal temperature of 80° C.

[0116] As soon as the temperature had reached 50° C., 126.2 g of 25% byweight aqueous sodium hydroxide solution (0.7888 mol of NaOH) andseparately 200 g of water were gradually added concurrently and thebatch was then diluted with 300 g of water. Isopropanol was distilledoff during the hydrolysis. The remaining isopropanol was removed at 85°C. under a pressure of 700 mbar to leave a slightly cloudy, reddishbrown solution having a solids content of 14.2%. The K value of thecopolymer was 24.9 (determined in 1% aqueous solution at 25° C.).

COMPARATIVE EXAMPLE 1

[0117] Copolymer prepared from 31 mol % of ethyl α-acetoxyacrylate and69 mol % of acrylic acid.

[0118] In a 250 ml capacity multi-neck glass flask equipped with areflux condenser, two dropping funnels and an internal thermometer, aninitial charge of 20 g of isopropanol was heated to an internaltemperature of 85° C. by means of an oil bath under nitrogen atmosphere.A monomer stream comprising a mixture of 39.5 g (0.25 mol) of ethylα-acetoxyacrylate, 39.5 g (0.5486 mol) of acrylic acid and 50 g ofisopropanol and an initiator stream comprising a mixture of 13.2 g of30% by weight hydrogen peroxide and 25 g of water were then addedconcurrently, the monomer stream being metered into the reaction vesselin the course of three hours and the initiator stream in the course ofsix hours. On completion of the initiator addition the reaction mixturewas postpolymerized for an hour to form a clear, highly viscous, lightyellow mass which was diluted with 60 g of isopropanol and 30 g of waterto form an almost colorless clear viscous solution. The solids contentof the solution was 52.0%. The copolymer had a K value of 25.4(determined in 1% solution in acetone at 25° C.).

Hydrolysis

[0119] The above-obtained reaction mixture was hydrolyzed in thehydrolysis vessel described in the inventive example 1 at an internaltemperature of 80° C. by addition of 176 g of 25% by weight aqueoussodium hydroxide solution (1.1 mol of NaOH). The sodium hydroxidesolution was added dropwise in the course of 15 minutes. At the sametime isopropanol was distilled off until the internal temperature hadrisen to 100° C. The mixture was subsequently maintained at 100° C. forone hour. It was then diluted with water until the light yellow viscoussolution had become clear. This required about 150 g of water. Thesolution had a solids content of 44.5 g. The copolymer had a K value of34.0 (determined in 1% aqueous solution at 25° C.).

COMPARATIVE EXAMPLE 2

[0120] Homopolymer prepared from ethyl α-acetoxyacrylate.

[0121] In a 250 ml capacity multi-neck glass flask equipped with apaddle stirrer, a reflux condenser, two dropping funnels and an internalthermometer, an initial charge of 80 g of isopropanol and 120 g (0.7595mol) of ethyl α-acetoxyacrylate was heated to 85° C. by means of an oilbath under a nitrogen atmosphere. A mixture of 20 g of 30% by weighthydrogen peroxide and 20 g of water was metered in over five hours. Oncompletion of the addition of the initiator the reaction mixture waspostpolymerized for 1.5 hours and diluted with 80 g of isopropanol and40 g of water to leave a light yellow, slightly cloudy, viscous solutionof a homopolymer of ethyl α-acetoxyacrylate having a solids content of26.5%. The polymer had a K value of 27.5 (determined in 1% solution inacetone at 25° C.).

Hydrolysis

[0122] 170 g of the above-described solution of the homopolymer wereinitially charged to the hydrolysis apparatus described in inventiveexample 1, heated to an internal temperature of 70° C. and admixed with176.7 g of 25% by weight aqueous potassium hydroxide solution (0.7874mol of KOH{circumflex over (=)}110% of the amount of base theoreticallyrequired for complete saponification). At the same time isopropanol wasdistilled off until the internal temperature had risen to 100° C. Themixture was then stirred at 100° C. for two hours and diluted with alittle water to form a clear reddish brown solution. The solids contentof the polymer solution was 28.6%. The thus obtained homopolymer ofα-hydroxyacrylic acid had a K value of 19.7 (determined in 1% aqueoussolution at 25° C.).

COMPARATIVE EXAMPLE 3

[0123] Copolymer prepared from 35 mol % of ethyl α-acetoxyacrylate and65 mol % of vinyl acetate.

[0124] In a 250 ml capacity multi-neck glass flask equipped with areflux condenser, two dropping funnels and an internal thermometer aninitial charge of 25 g of toluene was heated to 75° C. by means of anoil bath under a nitrogen atmosphere. As soon as 75° C. was reached, amonomer stream comprising a mixture of 40 g (0.2532 mol) of ethylα-acetoxyacrylate and 40 g (0.4651 mol) of vinyl acetate and aninitiator stream comprising a mixture of 8.5 g of tert-butyl perpivalate(75% by weight in aliphatics) and 18 g of toluene were addedconcurrently, the monomers being metered in over five hours and theinitiator over six hours. On completion of the addition of the initiatorthe mixture was postpolymerized at 75° C. for two hours and diluted with80 g of acetone to leave a clear colorless polymer solution having asolids content of 36.6%. The K value of the copolymer was 11.2(determined in 1% solution in acetone at 25° C.).

Hydrolysis

[0125] 135 g of the above-described polymer solution in the hydrolysisapparatus described in inventive example 1 were admixed with 69.5 g of50% by weight aqueous sodium hydroxide solution (0.6194 mol of KOH) andstirred at 60° C. for 4 hours. The reaction mixture was then heated toan internal temperature of 100° C., the solvent was gradually distilledoff, and the batch was diluted with a total of 400 g of water added alittle at a time to afford a clear dark red solution of a copolymer. Thesolids content of the solution was 16.5%. The copolymer had a K value of11.0 (determined in 1% aqueous solution at 25° C.).

[0126] The polymers prepared in the inventive and comparative exampleswere tested for bleach stabilization, dispersing power and ash reductionperformance according to the following methods:

Bleach Stabilization

[0127] The test was carried out in a phosphate-free laundry detergentformulation of the following composition (in % by weight):

[0128] 16.7% of sodium C₁₂-alkylbenzenesulfonate (50% by weight aqueoussolution)

[0129] 6.7% of addition product of 11 mol of ethylene oxide with 1 molof tallow fatty alcohol

[0130] 16.7% of sodium perborate]4 H₂O

[0131] 33.3% of zeolite A

[0132] 2.92% of copolymer of acrylic acid and maleic acid in weightratio of 50:50 (MW=50000)

[0133] 22.68% of sodium sulfate

[0134] 1% of the tetrasodium salt of 2,6-bis(N,N-(diaceticacid)aminomethyl)-4-isododecylphenol or tetrasodiumethylenediaminetetraacetate (EDTA) as comparative compound

[0135] Laundry detergent concentration was 6.2 g/l using 25° Germanhardness water. Decomposition was initiated by adding 5 ppm of Cu²⁺ tothe hot detergent liquor at 60° C. The residual peroxide content after 1h at 60° C. is reported in the table as bleach stabilization.

Determination of Calcium Binding Power (CBP)

[0136] Principle of Measurement

[0137] The inhibiting effect of complexing agents or dispersants on theprecipitation of calcium carbonate is determined by turbidity titration.The in-test substance is initially charged and titrated with calciumacetate solution in the presence of sodium carbonate. The end point isindicated through formation of the calcium carbonate precipitate. Use ofa sufficient amount of sodium carbonate ensures that the measurementwill provide a correct result even when the effect is due not just tocalcium ions being complexed but to calcium carbonate being dispersed.This is because if insufficient sodium carbonate is used there is adanger that the dispersing power of the product is not exhausted. Inthis case the titration end point is determined by the precipitation ofthe calcium salt of the in-test compound.

[0138] During the titration, the change in the light transmittance ismonitored by means of an optical fiber photometer. In the latter, alight beam passed through a glass fiber into the solution is reflectedat a mirror and the intensity of the reflecting light is measured.

[0139] Reagents

[0140] 0.25 M Ca(OAc)₂ solution

[0141] 10% by weight of Na₂CO₃ solution

[0142] 1 N NaOH solution

[0143] 1% by weight hydrochloric acid

[0144] Procedure

[0145] 1 g of active substance (A.S.) in the form of the trisodium saltis dissolved in 100 ml of distilled H₂O. 10 ml of 10% by weight Na₂CO₃solution are then added. The solution is automatically titratedcontinuously with 0.25 M Ca(OAc)₂ solution at 0.2 ml/min at roomtemperature (RT) and a pH of 11 (kept constant during the titration) andat 80° C. and a pH of 10.

[0146] Calculation

[0147] Amount mg of CaCO₃/g of A.S.=consumption of Ca(OAc)₂ solution inml×25. The end point is the 1st point of deflection of the automatictitration curve.

Ash Reduction

[0148] The incrustation-inhibiting effect (ash reduction) of thepolymers was tested in each case in the following laundry detergentformulation as additive: Laundry detergent formulation Parts by weightLinear dodecylbenzenesulfonate 6 C₁₂C₁₈-alkyl sulfate 2 C₁₃C₁₅ oxoalcohol with 7 EO 7 Soap 1 Na metasilicate × 5.5 H₂O 3.5 Zeolite A 36 Nacarbonate 12 Tetraacetylethylenediamine 3.5 (TAED) Na perboratemonohydrate 15 Carboxymethylcellulose (CMC) 1.5 Na sulfate 3 Water 4.5Additive 5

[0149] The above-described laundry detergent formulation contained 5% byweight of the copolymers to be tested for incrustation inhibition. Thethus prepared laundry detergent formulations were used to wash testcloths made of cotton. After washing, the ash content of the cloths wasdetermined by ashing 5 g of the test cloth at 700° C. for 2 hours.

[0150] The effect (W) of the laundry detergent additive in the Aformulation is reported in percent effectiveness, where 0% effectcorresponds to the ash content without incrustation inhibitor, i.e.without laundry detergent additive (A without) and 100% effectcorresponds to the ash content of the cloth before washing (A null).

[0151] The effect W of the additive is calculated from the determinedash content (A additive) by the following equation:$W = {\left( {1 - \frac{\left( {A - {Additive}} \right) - \left( {A - {null}} \right)}{\left( {A - {without}} \right) - \left( {A - {null}} \right)}} \right) \times {100\quad\lbrack\%\rbrack}}$

[0152] The following washing conditions were used: Apparatus:Launder-O-meter from Atlas Number of wash cycles: 15 Wash liquor: 250 gWater hardness: 4 mmol per liter (Ca:Mg = 4:1) Washing time: 30 min at60° C. (including heating time) Liquor ratio: 12.5:1 Test cloth: Cottoncheese cloth Detergent concentration: 4.5 g/l Ash null value: 0.04% byweight EMPA 211 0.09% by weight (Swiss materials testing institute atSt. Gallen, Switzerland)

[0153] The ash reduction test gave the following results: TABLE BleachCBP [mg of Ash stabilization CaCO₃/g of reduction Example No. (Cu) [%]polymer] [%] Inv. 1 87.7 670 30.26 Inv. 2 91.4 685 27.35 Inv. 3 89.4 63518.72 Inv. 4 77.7 500 44.16 Inv. 5 85.6 660 38.31 Inv. 6 85.6 580 28.66Inv. 7 89.9 500 44.2 Comp. 2 92.2 250 −21.5 Comp. 1 77.3 220 −4.9 Comp.3 66.6 165 19.3 Blank value 10 0 0 (no added polymer)

We claim:
 1. Multifunctional polymers containing polymerized units of(a) α-acyloxyacrylonitrile, α-haloacrylic acid, α-acyloxyacrylic esterand/or α-hydroxyacrylic acid, (b) monoethylenically unsaturatedcarboxylic acids, (c) vinyl esters of saturated aliphatic monocarboxylicacids and/or vinyl alcohol and optionally (d) other monoethylenicallyunsaturated monomers copolymerizable with said monomers (a) to (c) andoptionally (e) crosslinkers containing at least two ethylenicallyunsaturated double bonds having a K value of at least 7 (determinedafter H. Fikentscher in acetone at 25° C. and a polymer concentration of1% by weight) and whose monomer units (a) and (c) are if desiredpartially or completely hydrolyzed.
 2. Multifunctional polymers asclaimed in claim 1, containing polymerized units of (a) from 2 to 98 mol% of α-acyloxyacrylonitrile, α-haloacrylic acid, α-acyloxyacrylic esterand/or α-hydroxyacrylic acid, (b) from 1 to 95 mol % of at least onemonoethylenically unsaturated carboxylic acid, (c) from 1 to 90 mol % ofat least one vinyl ester of saturated aliphatic monocarboxylic acidsand/or vinyl alcohol, (d) from 0 to 20 mol % of other monoethylenicallyunsaturated monomers copolymerizable with said monomers (a) to (c) and(e) from 0 to 10 mol % of a crosslinker containing at least twoethylenically unsaturated double bonds, the mol % ages always adding upto
 100. 3. Multifunctional polymers as claimed in claim 1 or 2,containing polymerized units of (a) from 5 to 95 mol % ofα-acyloxyacrylonitrile, α-haloacrylic acid, α-acyloxyacrylic esterand/or α-hydroxyacrylic acid, (b) from 2 to 90 mol % of at least onemonoethylenically unsaturated carboxylic acid, (c) from 2 to 70 mol % ofat least one vinyl ester of saturated aliphatic monocarboxylic acidsand/or vinyl alcohol and (d) from 0 to 15 mol % of othermonoethylenically unsaturated monomers copolymerizable with saidmonomers (a) to (c), the mol % ages always adding up to
 100. 4.Multifunctional polymers as claimed in any of claims 1 to 3, containingpolymerized units of (a) from 10 to 90 mol % of α-acyloxyacrylonitrile,α-haloacrylic acid, α-acyloxyacrylic ester and/or α-hydroxyacrylic acid,(b) from 5 to 80 mol % of at least one monoethylenically unsaturatedcarboxylic acid, (c) from 5 to 60 mol % of at least one vinyl ester ofsaturated aliphatic monocarboxylic acids and/or vinyl alcohol and (d)from 0 to 10 mol % of other monoethylenically unsaturated monomerscopolymerizable with said monomers (a) to (c), the mol % ages alwaysadding up to
 100. 5. Multifunctional polymers as claimed in any ofclaims 1 to 4, containing polymerized units of (a) from 5 to 95 mol % ofα-hydroxyacrylic acid, amended sheet (b) from 2 to 90 mol % of acrylicacid, methacrylic acid, maleic acid and/or maleic anhydride, and (c)from 2 to 70 mol % of vinyl acetate and/or vinyl alcohol, the mol % agesalways adding up to
 100. 6. Multifunctional polymers containingpolymerized units of (a) α-hydroxyacrylic acid, (b) monoethylenicallyunsaturated carboxylic acids, (c) partially or completely hydrolyzedvinyl esters of saturated aliphatic monocarboxylic acids and optionally(d) other monoethylenically unsaturated monomers copolymerizable withsaid monomers (a) to (c) and optionally (e) crosslinkers containing atleast two ethylenically unsaturated double bonds and having a K value ofat least 6 (determined after H. Fikentscher in water at 25° C. and apolymer concentration of 1% by weight).
 7. A process for preparingmultifunctional polymers as claimed in any of claims 1 to 6, whichcomprises copolymerizing monomer mixtures of (a) α-acyloxyacrylonitrile,α-haloacrylic acid and/or α-acyloxyacrylic ester, (b) monoethylenicallyunsaturated carboxylic acids, (c) vinyl esters of saturated aliphaticmonocarboxylic acids and optionally (d) other monoethylenicallyunsaturated monomers copolymerizable with said monomers (a) to (c) andoptionally (e) crosslinkers containing at least two ethylenicallyunsaturated double bonds in the presence of polymerization initiatorsthat form free radicals and if desired partially or completelyhydrolyzing the polymerized monomer units (a) and (c) in the copolymersthus obtainable.
 8. A process as claimed in claim 7, wherein monomermixtures of (a) from 2 to 98 mol % of α-acyloxyacrylonitrile,α-haloacrylic acid and/or α-acyloxyacrylic ester, (b) from 1 to 95 mol %of monoethylenically unsaturated carboxylic acids, (c) from 1 to 90 mol% of at least one vinyl ester of an aliphatic monocarboxylic acid, (d)from 0 to 20 mol % of other monoethylenically unsaturated monomerscopolymerizable with said monomers (a) to (c) and (e) from 0 to 10 mol %of a crosslinker containing at least two ethylenically unsaturateddouble bonds, the percentages (a) to (e) always adding up to 100, arecopolymerized and the units (a) and (c) in the copolymers thusobtainable are partially or completely hydrolyzed.
 9. A process asclaimed in claim 7 or 8, wherein (a) from 5 to 95 mol % ofα-acyloxyacrylonitrile, α-chloroacrylic acid and/or α-acetoxyacrylicester, (b) from 2 to 90 mol % of acrylic acid, methacrylic acid, maleicacid and/or maleic anhydride, and (c) from 2 to 70 mol % of vinylacetate are copolymerized, the mol % ages always adding up to 100, andthe polymerized units (a) and (c) in the copolymers are partially orcompletely hydrolyzed.
 10. Use of the multifunctional polymers asclaimed in any of claims 1 to 6 in laundry detergents and cleaners, tobind polyvalent metal ions, as a stabilizer in textile bleaching and thebleaching of pulp for papermaking.